There are 5000 car spaces available in Carlton. Of these, 2100 give residents priority over non-residents by allowing them to overstay posted time limits. Just 287 spaces are reserved for residents only.

"It will get worse if we don't do anything," said Cr Catherine Ng, who chairs the council's planning and development committee. "With (forecast) growth . . . we could not find enough space for these cars."

The parking permit scheme was relaxed in 1993 to allow permits to be used on visitors' cars. The council fears the system has been abused.

Cr Ng said some residents had complained that multi-use permits had been sold on the black market. This type of permit now accounts for half the residential permits issued.

The council has issued an options paper for public comment, suggesting such possible solutions as: